Changes for page KerberosAndLDAP

Summary

• Page properties (1 modified, 0 added, 0 removed)

Details

Page properties

Content

...	...	@@ -1,75 +1,94 @@
1	1	= Debian =
2	2
3		-The guide I followed was [[https:~~/~~/wiki.debian.org/LDAP/OpenLDAPSetup#Kerberos>>https://wiki.debian.org/LDAP/OpenLDAPSetup#Kerberos]] which while it worked required some minor tweaks. I obtained edit privileges for the Debian Wiki and updated the guide with the fixes that I found. I however have a Synology NAS and that can run an LDAP Server. So this guide differs a little from the upstream Debian Guide.
	3	+The guide I followed was https://wiki.debian.org/LDAP/OpenLDAPSetup#Kerberos[[https://wiki.debian.org/LDAP/OpenLDAPSetup#Kerberos]] which while it worked required some minor tweaks. I obtained edit privileges for the Debian Wiki and updated the guide with the fixes that I found. I however have a Synology NAS and that can run an LDAP Server. So this guide differs a little from the upstream Debian Guide.
4	4
5		-First, install the packages containing the LDAP-enabled Kerberos servers ([[krb5-kdc-ldap>>url:https://packages.debian.org/krb5-kdc-ldap]] and [[krb5-admin-server>>url:https://packages.debian.org/krb5-admin-server]]) and the [[schema2ldif>>url:https://packages.debian.org/schema2ldif]] tool:
	5	+I will assume that you have installed the LDAP Server package on your NAS and gone through initial configuration steps, so it has a domain, there is a DN you can bind as and so forth. The Synology NAS can be leveraged for a multitude of things, and running DNS, DHCP, WebServices and Containers are but a few.
6	6
7		-{{{ $ sudo apt install krb5-kdc-ldap krb5-admin-server schema2ldif }}}
8	8
	8	+First, install the packages containing the LDAP-enabled Kerberos servers ([[krb5-kdc-ldap>>url:https://packages.debian.org/krb5-kdc-ldap]] and [[krb5-admin-server>>url:https://packages.debian.org/krb5-admin-server]]) and the [[schema2ldif>>url:https://packages.debian.org/schema2ldif]] tool on your Debian host:
9	9
10		-Then load the ##kerberos## schema:
	10	+(% style="color:red" %)
	11	+##{{{$ sudo apt install krb5-kdc-ldap krb5-admin-server schema2ldif}}}##
11	11
12		-{{{$ zcat /usr/share/doc/krb5-kdc-ldap/kerberos.openldap.ldif.gz | ldapadd -H ldap:~/~/nas.fqdn/ -D uid=root,cn=users,dc=example,dc=com
13	13
14		-adding new entry "cn=kerberos,cn=schema,cn=config"
	14	+Then load the ##kerberos## schema:
15	15
16		-}}}
	16	+(% style="color:red" %)
	17	+##{{{$ zcat /usr/share/doc/krb5-kdc-ldap/kerberos.openldap.ldif.gz | ldapadd -H ldap://nas.fqdn/ -D uid=root,cn=users,dc=example,dc=com -W}}}##
	18	+##{{{Enter LDAP Password:}}}##
	19	+##{{{adding new entry "cn=kerberos,cn=schema,cn=config"}}}##
	20	+##{{{$}}}##
17	17
18	18
19		-And add an index on the ##krbPrincipalName## (improves performance and also suppresses some log messages if ##slapd## is configured to log more than default) for the database(s) where you intend to store Kerberos data:
	23	+Having an index on the ##krbPrincipalName## improves performance and also suppresses some log messages if ##slapd## is configured to log more than default for the database(s) where you intend to store Kerberos data. As this is OpenLDAP on the Synology, it does not use ##mdb## format, it uses ##bdb##:
20	20
21		-{{{# ldapmodify -H ldap:~/~/nas.fqhn <<EOF
	25	+(% style="color:red" %)
	26	+##{{{$ ldapmodify -H ldap://nas.fqdn/ -D uid=root,cn=users,dc=example,dc=com -W <<EOF}}}##
	27	+##{{{dn: olcDatabase={1}bdb,cn=config}}}##
	28	+##{{{add: olcDbIndex}}}##
	29	+##{{{olcDbIndex: krbPrincipalName eq,pres,sub}}}##
	30	+##{{{EOF}}}##
	31	+##{{{Enter LDAP Password:}}}##
	32	+##{{{modifying entry "olcDatabase={1}bdb,cn=config"}}}##
	33	+##{{{$}}}##
22	22
23		-dn: olcDatabase={1}bdb,cn=config
24	24
25		-add: olcDbIndex
	36	+Next, you need to create and configure two entries which will be used by the Kerberos servers to connect to OpenLDAP. As you will not run the Kerberos KDC and Admin Server on the same host as OpenLDAP, these steps are required. In order to keep things nicely separated, everything will be created under a separate ##organizationalUnit##.
26	26
27		-olcDbIndex: krbPrincipalName eq,pres,sub
	38	+(% style="color:red" %)
	39	+##{{{$ ldapadd -H ldap://nas.fqdn/ -D uid=root,cn=users,dc=example,dc=com -W <<EOF}}}##
	40	+##{{{dn: ou=Services,dc=example,dc=com}}}##
	41	+##{{{objectClass: organizationalUnit}}}##
	42	+##{{{objectClass: top}}}##
	43	+##{{{ou: Services}}}##
	44	+## ##
	45	+##{{{dn: ou=kerberos,ou=Services,dc=example,dc=com}}}##
	46	+##{{{objectClass: organizationalUnit}}}##
	47	+##{{{objectClass: top}}}##
	48	+##{{{ou: kerberos}}}##
	49	+## ##
	50	+##{{{dn: uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com}}}##
	51	+##{{{uid: kdc}}}##
	52	+##{{{objectClass: account}}}##
	53	+##{{{objectClass: simpleSecurityObject}}}##
	54	+##{{{userPassword: {CRYPT}x}}}##
	55	+##{{{description: Kerberos KDC Account}}}##
	56	+## ##
	57	+##{{{dn: uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}##
	58	+##{{{uid: kadmin}}}##
	59	+##{{{objectClass: account}}}##
	60	+##{{{objectClass: simpleSecurityObject}}}##
	61	+##{{{userPassword: {CRYPT}x}}}##
	62	+##{{{description: Kerberos Admin Server Account}}}##
	63	+##{{{EOF}}}##
	64	+##{{{Enter LDAP Password:}}}##
	65	+## ##
	66	+##{{{adding new entry "ou=Services,dc=example,dc=com"}}}##
	67	+## ##
	68	+##{{{adding new entry "ou=kerberos,ou=Services,dc=example,dc=com"}}}##
	69	+## ##
	70	+##{{{adding new entry "uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com"}}}##
	71	+## ##
	72	+##{{{adding new entry "uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com"}}}##
28	28
29		-EOF
30	30
31		-modifying entry "olcDatabase={1}bdb,cn=config"
	75	+Now, it was at this point that I had a problem, because the LDAP server on the Synology did not like adding users with placeholder passwords, because Synology puts in place password policies. I ended up working around it using a different construct:
32	32
33		-}}}
	77	+(% style="color:red" %)
	78	+##{{{dn: cn=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}##
	79	+##{{{sn: kadmin}}}##
	80	+##{{{cn: kadmin}}}##
	81	+##{{{objectClass: person}}}##
	82	+##{{{objectClass: pwdPolicy}}}##
	83	+##{{{pwdAttribute: userPassword}}}##
	84	+##{{{pwdMinLength: 8}}}##
	85	+##{{{pwdCheckQuality: 2}}}##
	86	+##{{{pwdPolicySubentry: cn=kadmin,ou=kerberos,ou=Services,dc=example,dc=com}}}##
	87	+##{{{userPassword: {SSHA}<hashed password>}}}##
	88	+##{{{description: Kerberos Admin Server Account}}}##
34	34
	90	+and that seems to have worked out fine as my KDC is fully functioning.
35	35
36		-Next, you need to create and configure two entries which will be used by the Kerberos servers to connect to OpenLDAP. If you are running Kerberos and OpenLDAP on the same system, these steps are optional, but recommended. In order to keep things nicely separated, everything will be created under a separate ##organizationalUnit##. Note that a simple bind (##-x -D##) is used instead of an ##EXTERNAL## bind since write access to the dc=example,dc=com DIT is necessary:
	92	+It required modifying the rest of the guide with the fact that it no longer was ##uid=kadmin## and ##uid=kdc##, but rather ##cn=kadmin## and ##cn=kdc##. The most important thing is that it works. As an aside, I am not sure it is required to have two nested Organisation Units, ##Services## and ##kerberos## - so I will likely re-deploy and get rid of the ##Services## Organisational Unit altogether. It shortens the DN's used for binds to LDAP and limits the risk for typos. I also find it highly unlikely that deploying this in a real organisation that there would be an existing Organisational Unit called '##kerberos##' while the risk for there being an existing department called '##Services##' is much more likely.
37	37
38		-
39		-{{{# ldapadd -x -D cn=admin,dc=example,dc=com -W <<EOF
40		-dn: ou=Services,dc=example,dc=com
41		-objectClass: organizationalUnit
42		-objectClass: top
43		-ou: Services
44		-
45		-dn: ou=kerberos,ou=Services,dc=example,dc=com
46		-objectClass: organizationalUnit
47		-objectClass: top
48		-ou: kerberos
49		-
50		-dn: uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com
51		-uid: kdc
52		-objectClass: account
53		-objectClass: simpleSecurityObject
54		-userPassword: {CRYPT}x
55		-description: Kerberos KDC Account
56		-
57		-dn: uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com
58		-uid: kadmin
59		-objectClass: account
60		-objectClass: simpleSecurityObject
61		-userPassword: {CRYPT}x
62		-description: Kerberos Admin Server Account
63		-EOF
64		-Enter LDAP Password: SECRET
65		-
66		-adding new entry "ou=Services,dc=example,dc=com"
67		-
68		-adding new entry "ou=kerberos,ou=Services,dc=example,dc=com"
69		-
70		-adding new entry "uid=kdc,ou=kerberos,ou=Services,dc=example,dc=com"
71		-
72		-adding new entry "uid=kadmin,ou=kerberos,ou=Services,dc=example,dc=com"}}}
73		-
74		-
75		-
	94	+A note on the above workaround. In order to add a password policy on ##kadmin## and ##kdc## in LDAP, they have to have an attribute that is "physical". And when adding that object class the entries could no longer be a ##uid##. Hence the ##sn## and ##cn## parts. I spent a fair time looking things up as whenever I thought I made progress, something else turned out to be a blocker. When you create the ##{SSHA}## password hash, use ##slappasswd## from the ##slapd## package.